When the input voltage is above the UVLO threshold and the EN voltage is above the enable threshold, the TPS56220x can operate in the normal switching modes. The TPS562201 and TPS562208 operate at a quasi-fixed frequency of about 580kHz under CCM mode when T_ON extension is not triggered. When input voltage V_IN < 7V and V_FB is lower than internal reference voltage, the switching frequency is allowed to smoothly drop to make T_ON extended to keep output voltage and improve the load transient performance. The minimum switching frequency is limited to about 200kHz.